1. Technical Field
The present invention relates to outputting of a 3D image and viewing thereof, and more particularly, to a power control technology of a 3D image viewing apparatus.
2. Description of the Related Art
A 3D image technology is adopted in various application fields such as information telecommunication, broadcasting, medical services, education and training, military affairs, games, animations, virtual reality, CAD, industrial technologies, etc., and is a core-based technology of the next-generation 3D multimedia information telecommunication commonly required in various fields.
In general, a 3D effect perceived by humans is generated by complex interaction of the degree of change in the thickness of crystalline lens depending on the location of an object to be observed, an angular difference between both eyes and an object, a difference in position and shape of objects viewed with right and left eyes, a disparity in vision generated by movement of the target, various effects by psychology and memory, etc. Among them, a binocular disparity generated due to positions of both the human's eyes that are spaced from each other in a horizontal direction by approximately 6 to 7 cm may be the most key factor of the 3D effect. That is, the target is viewed with an angular difference by the binocular disparity and images viewed by both eyes have different shapes due to the difference. When two images are transmitted to the brain through a retina, the brain accurately amalgamates information on two images with each other to feel an original 3D image.
3D image display apparatuses are classified into a glass type using special glasses and a non-glass type not using the special glasses. The glass type includes a color filter type separately selecting the images by using color filters having a mutual complementary relationship, a polarizing filter type separating a left-eye image and a right-eye image from each other using a light shielding effect by a combination of polarizing elements orthogonal to each other, and a shutter glass type to feel a 3D effect by alternately intercepting the left eye and the right eye to correspond to a synchronization signal projecting a left-eye image signal and a right-eye image signal to a screen.
Among them, the shutter glass type as a display method using the binocular disparity is a method perceiving spaciousness of images observed at different angles by a brain operation by synchronizing on and off operations of both left and right eyes of the glasses with provision of the image of the display apparatus.
However, in the shutter glass type, it is impossible to view a 3D image only by wearing a shutter glass and it is possible to view the 3D image only by synchronizing the on and off operations of the eyes with the display apparatus in a wired or wireless method. Accordingly, since the synchronization signal Vsync should be continuously received from the display apparatus for the synchronization, battery consumption is large.
Further, the existing shutter glass is configured to receive the synchronization signal primarily in an infrared-ray (IR) type. However, since infrared-rays have linearity, when an obstacle is provided between a transmitter of the display apparatus and a receiver of the shutter glass, transmission of the synchronization signal is interrupted, such that it is impossible to view an accurate 3D image. Further, a viewing range of the display apparatus is also narrowed due to the linearity of the infrared-rays.